Speaker apparatus and television set

ABSTRACT

A first feature of the present invention is that the opening of a sound output port  3   b  is smaller in area than the opening of a sound input port  3   a  in a horn  3 . A second feature is that the sound output port  3   b  of the horn  3  is located so as not to be in the way of a center axis of sound radiation from a speaker  2 . A third feature is that a length L of the horn  3  is set at 370 mm or below. A fourth feature is that the horn  3  is gradually narrowed such that vertical sections thereof from the sound input port  3   a  to the sound output port  3   b  respectively have areas based on a predetermined rule. 
     Thus, it is possible to realize a speaker apparatus in which a sound output port of a horn is smaller in area than a vibrating surface of a speaker while reproducing sound whose quality is equal or similar to that in conventional speaker apparatus, and a television set equipped with the speaker apparatus.

TECHNICAL FIELD

The present invention relates to speaker apparatus and television sets,and more specifically to a speaker apparatus provided with a horn havingan output port smaller in area than a vibrating surface of a speaker,and a television set equipped with the speaker apparatus.

BACKGROUND ART

In general, it is the best that a speaker apparatus directly outputssound from a speaker without utilizing a horn. A horn, however, iscommonly used in a speaker apparatus because of the limited size of acabinet such as a television set and personal computer where the speakerapparatus is installed.

For example, in the case where a speaker apparatus is integrated in atelevision set and then speakers are placed on both sides of a cathoderay tube (CRT) thereof , the width of the television set is uselesslyenlarged. Therefore, in a conventional television set, a speakerapparatus provided with a horn having a slim and long output port iswidely used to minimize the width of the television set.

Such speaker apparatus provided with horns having slim and long outputports include, for example, “Speaker system for television set”disclosed in Japanese Utility Model Publication No. 5-20475, and“Speaker system for television set” disclosed in Japanese PatentLaying-Open No. 7-177443.

In FIG. 7, shown is a perspective view of “Speaker system for televisionset” disclosed in Japanese Patent Laying-Open No. 7-177443.

In the above-described conventional speaker apparatus, an output port ofa horn is required to be larger in area than a vibrating surface of aspeaker in order to secure a sufficient sound pressure level. Theconfiguration of the conventional speaker apparatus allows a televisionset to be narrower in width. However, the height of the television setmust be increased due to the decreased width in order to ensure the areaof the output port to be larger than the area of the vibrating surfaceof the speaker. Consequently, the television set has a complicatedstructure, and a molding die for the speaker apparatus is elaborate andexpensive, which makes it difficult to produce the speaker apparatuswith a multiple cavity die. Besides, the speaker apparatus occupies alarge portion in the television set as a result. This leads to a problemthat the structure of the television set can not be freely designed.

Therefore, an object of the present invention is to provide a speakerapparatus in which a sound output port of a horn is smaller in area thana vibrating surface of a speaker while reproducing sound whose qualityis equal or similar to that in the conventional art, and a televisionset equipped with the speaker apparatus.

DISCLOSURE OF THE INVENTION

The present invention has the following features to attain theabove-described object.

A second aspect is directed to a speaker apparatus comprising a speakerwith a horn,

the horn has a shape in which:

a sound input port is attached to a vibrating surface of the speaker,and a sound output port is smaller in area than the sound input port;

the length from the sound input port to the sound output port is notmore than 370 mm;

when representing the area of the opening of the sound input port as A,the area of the opening of the sound output port as B, the length of thehorn as L, a distance from the sound input port as X, and an arbitraryinteger of not less than 1 as C,

the area Y of the vertical section, of the horn, being parallel to aplane of the sound input port at the distance X can be expressed by thefollowing equation;

Y=(A−B)*(L−X)^(c) /L ^(c) +B; and

 the sound output port is formed in a position where a center axis ofthe sound radiated from the speaker does not impinge against an innerwall of the horn.

As described in the above, according to the second aspect, it ispossible to make an opening of the sound output port smaller in areathan an opening of sound input port in the horn, and at the same time,suppress resonance of sound outputted from the speaker within the horndown to its second resonance frequency and obtain better sound pressureproperties as compared with the conventional speaker apparatus. As aresult, preferable sound with less dip can be reproduced.

As stated above, the second aspect indicates a preferable length of thehorn in the first aspect. Thus, the resonance of sound outputted fromthe speaker can be suppressed within the horn down to its secondresonance.

According to a third aspect, in the second aspect, wherein in thepredetermined rule,

when representing an area of an opening of the sound input port as A, anarea of an opening of the sound output port as B, a length of the hornas L, a distance from the sound intput port as X, and an arbitraryinteger of not less than 1 as C,

an area Y of the vertical section of the horn at the distance X can beexpressed by a following equation;

Y=(A−B)×(L−X)^(c) /L ^(c) +B.

As mentioned in the foregoing, the third aspect presents a typicalequation for calculating each area of the vertical sections of the hornin the second aspect.

According to a fourth aspect, in the second aspect, the shapes of thesound input port and the output port and the vertical section of thehorn are any one of circular, oval, or polygonal form, or a combinationof the above-described forms.

As described above, according to the second aspect, in the secondaspect, it is possible to reduce unwanted sound produced by theresonance within the horn and the strength of installation structure ofthe horn.

According to a fifth aspect, in the fourth aspect, the opening of thesound input port of the horn is equal to or smaller in area than thevibrating surface of the speaker.

As described above, according to the fifth aspect, in the fourth aspect,it is possible to prevent sound from resonating within the horn.

According to a sixth aspect, in the fifth aspect,

another horn is further provided to the output port of the horn whilekeeping the entire length no more than 370 mm, wherein

the vertical sectional area of the another horn is constant or a soundoutput port thereof being broader than a sound input port thereof.

As described above, according to the sixth aspect, in the fifth aspect,the horn can be designed more flexibly.

A seventh aspect is directed to a television set equipped with thespeaker apparatus according to any one of the following (a), (b) or (c):

(a) A speaker apparatus, wherein the horn has a shape in which:

a sound input port is attached to a vibrating surface of the speaker,and a sound output port portion for outputting sound inputted to thesound input port is smaller in area than the sound input port;

the length from the sound input port to the sound output port is notmore than 370 mm;

when representing the area of the opening of the sound input port as A,the area of the opening of the sound output port as B, the length of thehorn as L, a distance from the sound input port as X, and an arbitraryinteger of not less than 1 as C,

the area Y of the vertical section, of the horn, being parallel to theplane of the sound input port at the distance X can be expressed by afollowing equation;

Y=(A−B)×(L−X)^(c) /L ^(c) +B; and

 the sound output port is formed in a position where a center axis ofthe sound radiated from the speaker does not impinge against an innerwall of the horn.

(b) The speaker apparatus as described above in (a), wherein

the shapes of the sound input port and the sound output port and thevertical section of the horn are any one of circular, oval, or polygonalfrom, or a combination of the above-described forms.

(c) The speaker apparatus as described above in (b), wherein

the opening of the sound input port of the horn is equal to or smallerin area than the vibrating surface of the speaker;

wherein another horn is further provided to the output port of the hornwhile keeping the entire length no more than 370 mm; and

wherein the vertical sectional area of the another horn is constant or asound output port thereof being broader than a sound input port thereof.

As described above, the seventh aspect is directed to the television setequipped with the speaker apparatus described in any one of the second,fourth and sixth aspects. The television set can dispose a sound outputport in empty space in the front of a cabinet thereof, and reduce thewidth thereof by being equipped with the speaker apparatus described inany one of the second, fourth and sixth aspects. Besides, since thestructure of the speaker apparatus can be simplified, a molding die forthe speaker apparatus can be also simplified. This enables production ofspeaker apparatus with a single multiple cavity die. Consequently, it ispossible to provide greater flexibility with the design of thetelevision set.

According to a tenth aspect, in the ninth aspect, wherein

shapes of the sound input port and the sound output port and thevertical section of the horn are any one of circular, oval, orpolygonal, or combination thereof.

According to an eleventh aspect, in the tenth aspect, wherein

the opening of the sound input port of the horn is equal to or smallerin area than the vibrating surface of the speaker.

According to a twelfth aspect, in the eleventh aspect, wherein

another horn whose vertical sectional area is constant, or broadertoward a sound output port thereof is further added to the output portof the horn.

As described above, the seventh to twelfth aspects are directed to thetelevision set equipped with the speaker apparatus according to thefirst to sixth aspects. The television set can dispose a sound outputport in empty space in the front of a cabinet thereof, and reduce thewidth thereof by being equipped with the speaker apparatus according tothe first to sixth aspects. Besides, since the structure of the speakerapparatus can be simplified, a molding die for the speaker apparatus canbe also simplified. This enables production of speaker apparatus with asingle multiple cavity die. Consequently, it is possible to providegreater flexibility with the design of the television set.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing a structure of a speaker apparatus accordingto an embodiment of the present invention;

FIG. 2 is a diagram showing a section view of the speaker apparatus 1obtained by cutting the horn 3 shown in FIG. 1 along a D—D line;

FIGS. 3A and 3B are diagrams each showing a position of the sound outputport 3 b with respect to an axis of sound radiation;

FIG. 4 is a diagram explaining a narrowing shape of the horn 3;

FIGS. 5A and 5B are diagrams each showing combination of the speakerapparatus 1 of the present invention and another horn;

FIGS. 6A and 6B are diagrams each showing a structure of a televisionset equipped with the speaker apparatus 1 according to the presentinvention; and

FIG. 7 is a diagram showing a structure of a television set equippedwith a conventional speaker apparatus.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 shows a structure of a speaker apparatus according to anembodiment of the present invention. In FIG. 1, a speaker apparatus 1according to the embodiment of the present invention comprises a speaker2 and a horn 3.

FIG. 2 shows a section view of the speaker apparatus obtained by cuttingthe horn 3 shown in FIG. 1 along a D—D line.

The speaker 2 is a general speaker unit having a diaphragm in acircular, oval, or rectangular shape. The horn 3 is shaped like a hollowtube as shown in FIG. 2. The horn 3 receives sound outputted from thespeaker 2 with one opening end (hereinafter, referred to as a soundinput port 3 a), and outputs the sound from the other opening end(hereinafter, referred to as a sound output port 3 b). A verticalsection through the horn 3 (that is, a section parallel to atwo-dimensional plane of the sound input port 3 a) is basically in acircular shape, but may be oval or polygonal if it satisfies conditionsdescribed below.

The speaker apparatus 1 according to the embodiment of the presentinvention is featured by the shape of the horn 3. The shape of the horn3 having the following features is described in sequence below withreference to FIGS. 3 to 5.

FIGS. 3A and 3B each show a position of the sound output port 3 b withrespect to an axis of sound radiation. FIG. 4 explains a narrowing shapeof the horn 3. FIGS. 5A and 5B each show combination of the speakerapparatus 1 of the present invention and another horn.

Firstly, a first feature of the shape is that in the horn 3, an openingof the sound output port 3 b is smaller in area than an opening of thesound input port 3 a (refer to FIG. 2).

This makes it possible to use the speaker 2 with a wide-bore regardlessof the size of a cabinet accommodating the same.

Next, a second feature of the shape is that the sound output port 3 b ofthe horn 3 is located so as not to be in the way of a center axis ofsound radiation from the speaker 2 (refer to FIG. 3A). Specifically, thesound output port 3 b is located in a position where a dust cap 4 formedin the center of the diaphragm of the speaker 2 can be viewed in itsentirety through the sound output port 3 b (refer to FIG. 3B).

Thus, a high-frequency sound can be directly radiated from the soundoutput port 3 b through the center portion of the speaker apparatus 1,and thereby sound can be outputted without being polarized.

Next, a third feature of the shape is that a length L of the horn 3(refer to FIG. 2) is determined such that sound properties of thespeaker apparatus 1 are equal or similar to those in the speaker 2without the horn 3. Note that the length L is preferably set at 370 mmor below. This value indicates a condition where the sound reproductionproperties of the speaker apparatus 1 with the horn 3 are equal orsimilar to those of the single speaker 2 without the horn 3, and isobtained by experiment.

This makes it possible to suppress resonance of sound outputted from thespeaker 2 within the horn 3 down to its second resonance frequency.

Furthermore, a fourth feature of the shape is that areas of verticalsections of the horn 3 from the sound input port 3 a to the sound outputport 3 b are gradually narrowed on the basis of a predetermined rule.The predetermined rule is, for example, expressed by an equation shownbellow.

Referring to FIG. 4, when representing an area of the opening of thesound input port 3 a as A, an area of the opening of the sound outputport 3 b as B, a length of the horn 3 as L, and a distance from thesound input port 3 a as X, an area Y of the vertical section of the horn3 at the distance X can be expressed as follows:

Y=(A−B)×(L−X)^(c) /L ^(c) +B

where a multiplier factor C for the distance X is a constant fordeciding the narrowing shape of the horn 3, and takes an integer of notless than 1 as a value.

As is clear from the above equation, the area Y of the vertical sectionof the horn 3 at the distance X becomes smaller while being inverselyproportional to the multiplier factor C for the distance X. For example,the area Y of the vertical section is narrowed along an inclined linearline as shown in FIG. 4 in the case where the factor C is equal to 1,and narrowed along an inclined quadric curve as shown in FIG. 1 in thecase where the factor C is equal to 2.

It should be noted that the multiplier factor C can be arbitrarily setaccording to purposes, but is preferably set at 2 for excellent soundreproduction.

In the case where the speaker 2 has an oval or rectangular shapeddiaphragm, in order to form the sound output port 3 b of the horn 3 in acircular shape, the horn 3 may be molded by gradually deforming thevertical section thereof from the shape of the diaphragm in the soundinput port 3 a to a circular shape of the sound output port 3 b.

As described in the foregoing, according to the speaker apparatus 1 inthe embodiment of the present invention, it is possible to make theopening of the sound output port 3 b smaller in area than the opening ofthe sound input port 3 a in the horn 3, and at the same time, suppressresonance within the horn 3 and obtain better sound pressure propertiesas compared with conventional speaker apparatus. As a result, sound withless dip can be reproduced.

This provides greater flexibility with the design of a television set,and the like.

Moreover, it is possible to further add another horn, whose verticalsection area is constant or broaden toward the sound output port, to thespeaker apparatus 1 of the present invention, on condition that thetotal length the speaker apparatus 1 falls within 370 mm or below whenthe distance from the sound input port 3 a to the sound output port 3 bof the horn 3 is not more than 370 mm (see FIGS. 5A and 5B).

Shown in FIGS. 6A and 6B are television sets each equipped with thespeaker apparatus 1 according to the above-mentioned embodiment of thepresent invention. FIG. 6A shows a front elevational view of thetelevision set, and FIG. 6B shows a section view of the television setobtained by cutting the television set along an E—E line.

As shown in FIGS. 6A and 6B, the speaker apparatus 1 according to theabove-mentioned embodiment of the present invention has another effect,in addition to the above-mentioned effects, that the sound output ports3 b can be disposed in empty space in a front operating panel of thetelevision set. Thus, the television set can be downsized with respectto its width.

Furthermore, the television set shown in FIG. 6 can suppress vibrationof its cabinet and use a base, on which the cabinet is mounted, as abaffle, thereby realizing preferable sound reproduction with lessunwanted sound.

INDUSTRIAL APPLICABILITY

As stated above, the speaker apparatus of the present invention can beused in a television set, display apparatus, and the like. The use ofthe speaker apparatus makes it possible to make a sound output port in ahorn smaller in area than a vibrating surface of a speaker whilereproducing sound whose quality is equal or similar to that inconventional speaker apparatus.

What is claimed is:
 1. A speaker apparatus comprising a speaker with ahorn, said horn has a shape in which: a sound input port is attached toa vibrating surface of said speaker, and a sound output port foroutputting sound inputted to the sound input port is smaller in areathan the sound input port; the length from said sound input port to saidsound output port is not more than 370 mm; when representing the area ofthe opening of said sound input port as A, the area of the opening ofsaid sound output port as B, the length of said horn as L, a distancefrom said sound input port as X, and an arbitrary integer of not lessthan 1 as C, the area Y of the vertical section, of said horn, beingparallel to a plane of said sound input port at the distance X can beexpressed by the following equation; Y=(A−B)×(L−X)^(c) /L ^(c) +B; and said sound output port is formed in a position where a center axis ofthe sound radiated from said speaker does not impinge against an innerwall of said horn.
 2. The speaker apparatus according to claim 1,wherein the shapes of said sound input port (3 a) and said output port(3 b) and said vertical section of said horn (3) are any one ofcircular, oval, or polygonal form, or a combination of the abovedescribed forms.
 3. The speaker apparatus according to claim 2, whereinthe opening of said sound input port of said horn is equal to or smallerin area than the vibrating surface of said speaker.
 4. The speakerapparatus according to claim 3, wherein another horn is further providedto said output port of said horn while keeping the entire length no morethan 370 mm, wherein said vertical section area of the another horn isconstant or a sound output port thereof being broader than a sound inputport thereof.
 5. A television set equipped with the speaker apparatus asclaimed in claim
 1. 6. A television set equipped with the speakerapparatus as claimed in claim
 2. 7. A television set equipped with thespeaker apparatus as claimed in claim 4.